I finally got around to trying a Triac to turn on and off an amp and it was a success. I am still looking for the down side of this mod. This mod should work on any amp and the power switch load will be reduced to around 120 ma and no arcing. The power switch will now last longer that you will. The test bed is a Lafayette LR9090 (Setton RS) series known for lunching on power switches. This switch had the NO contact for power "on" inside the switch gone, just smoky residue left. This special case required a relay NC contact for the PA Mute / protective relay dump on power "off". I moved the switch NC contact to NO position for the power on function. Triac used was a Littlefuse Q4025L6 (Mouser 576-Q4025L6) Rated 400VAC 25A RMS for highly inductive loads and tab isolated. Way over rated. Yea olde Fluke gives around 7A AC peak on the 100 ms scale at power "on" and idle current of 0.6A AC at low volume. The Triac data sheet is on Mouser: http://www.mouser.com/Search/Refine.aspx?Keyword=q4025 Note: Triac suffix L6 is a TO220 case isolated tab, if you prefer solder loops for a buck or so more the J6 suffix is a TO218X with loop leads and isolated tab. For me, the isolated tab and not having to bother with mica and screw isolator is worth a buck or 2. You? This is a difficult mod with an extensive parts list: 1 ea Triac 1 ea 100 ohm 1/2 watt resistor Remove the AC line power and transformer lead (and maybe switched rear outlet) from the power switch. Remove the RC snubber across the switch contacts. Mount the Triac in any handy location. AC power lead goes to M1 Transformer lead (and maybe switched rear outlet) goes to M2 Power switch: lead 1 100 Ohm resistor and goes to gate G lead 2 goes to M2 OK!, so I lied about being difficult I found a place on the chassis for the Triac that the leads would fit, drilled a mounting hole, soldered directly to the TO220 leads and used heat shrink over joint and lead. Initial testing was done by removing the transformer primary fuse and hooking up a 100W bulb for a load. After a bunch of switching the bulb on and off, I put the transformer fuse back in and tested and tested...... The amp has been switched on & off left on for days and no problems. On state voltage drop is 0.8 to 0.9 VAC which agrees with the data sheet curve Other benefits / thoughts: 1. Littlefuse calls these Triacs: Alternistor Triacs and they are designed for high inductive loads so no RC snubber is required. 2. Power "off" is always at a zero crossing so there is no arcing thus no voltage transients inside the amp to worry the power supply components. 3. Power "on" has no contact bounce arcing. It did not seem useful to add the extra parts for zero crossing turn on. 4. A 200V rated Triac would work, but why save a few pennies and give Murhpy a chance? 5. Lower current rating would work. 3000W @ 125 VAC switching capability is not needed, but see above 6. Triac off state leakage is 50 micro amps which is lower than the original RC filter across the power switch. 7. A MOV and / or RC filter on the incoming power is still necessary to protect the amp from the rest of the world. After more testing this mod will be refined with pictures and added to the LR9090 repair / upgrade thread. I hope to get some feed back about possible problems I have missed.